Nazdaneh Yarahmadi

Acrylonitrile butadiene styrene (ABS) is widely used as an engineering plastic, but its extensive use generates a significant amount of waste that is difficult to recycle due to the material’s complex composition. In this study, the physical recycling of ABS using the dissolution technique has been employed to separate the pure copolymer of styrene and acrylonitrile (SAN) from polybutadiene rubber (PBR) and other substances. The relationships between the properties and composition of the original ABS materials were investigated as a starting point and for reference values to evaluate the effects of recycling on the quality and safety of recycled materials. Three different ABS materials were used in the recycling process from which pure SAN polymers were produced. The recycled SANs were then melt-blended with fresh masterbatch. The final ABS materials had the same composition, which facilitated investigation of whether the use of SAN recycled from different sources results in any differences in the properties of the final ABS material. The results showed that all the properties of ABS materials made with recycled SAN are similar regardless of the source of SAN. Several chemical substances were quantified in the original ABS materials and in SAN polymers obtained through the recycling process. The substances were largely removed from all materials except one. The main conclusions from this study are that the quality of ABS materials made with recycled SAN is at the same level as that of virgin ABS and is independent of the source from which SAN comes. This study has also shown that chemical safety is satisfactory because the physical recycling process is able to remove most of the substances that were present in the original ABS materials.

ABS is widely used as engineering plastic, but extensive use generates a significant amount of waste which is difficult to recycle due to material's complex composition. Physical recycling of ABS using TNO Möbius dissolution technique has been used here to separate pure SAN polymer, from PBR, and other substances. Relationships between properties and composition of the original materials were investigated as a starting point for evaluation of the effects of recycling on the quality of recycled materials. Three ABS materials were used in the recycling process to produce pure SAN polymers. The recycled SANs were then melt-blended with fresh masterbatch. The final ABS ma-terials had the same composition which allowed to investigate whether SAN recycled from different sources causes differences in properties of the final ABS materials. All properties of ABS materials made with recycled SAN are similar regardless of the source of SAN. Substances were quantified in the original ABS materials and in SAN polymers obtained by the recycling process. The substances were largely removed from all materials except one. The main conclusions from this study are that SAN polymer obtained by physical recycling from different sources does not affect properties of the final ABS material and the TNO process successfully separates SAN from other substances.

It is generally recognized that the use of physical and digital information-based solutions for tracking plastic materials along a value chain can favour the transition to a circular economy and help to overcome obstacles. In the near future, traceability and information exchange between all actors in the value chain of the plastics industry will be crucial to establishing more effective recycling systems. Recycling plastics is a complex process that is particularly complicated in the case of acrylonitrile butadiene styrene (ABS) plastic because of its versatility and use in many applications. This literature study is part of a larger EU-funded project with the acronym ABSolEU (Paving the way for an ABS recycling revolution in the EU). One of its goals is to propose a suitable traceability system for ABS products through physical marking with a digital connection to a suitable data-management system to facilitate the circular use of ABS. The aim of this paper is therefore to review and assess the current and future techniques for traceability with a particular focus on their use for ABS plastics as a basis for this proposal. The scientific literature and initiatives are discussed within three technological areas, viz., labelling and traceability systems currently in use, digital data sharing systems and physical marking. The first section includes some examples of systems used commonly today. For data sharing, three digital technologies are discussed, viz., Digital Product Passports, blockchain solutions and certification systems, which identify a product through information that is attached to it and store, share and analyse data throughout the product’s life cycle. Finally, several different methods for physical marking are described and evaluated, including different labels on a product’s surface and the addition of a specific material to a polymer matrix that can be identified at any point in time with the use of a special light source or device. The conclusion from this study is that the most promising data management technology for the near future is blockchain technology, which could be shared by all ABS products. Regarding physical marking, producers must evaluate different options for individual products, using the most appropriate and economical technology for each specific product. It is also important to evaluate what information should be attached to a specific product to meet the needs of all actors in the value chain.